title: Effect of wine inhibitors on free pineapple stem bromelain activity in a model wine system.
abstract: The influence of potential inhibitors, naturally present in wine, on the activity of stem bromelain was investigated in order to evaluate the applicability of this enzyme for protein stabilization in white wine. Bromelain proteolytic activity was tested against a synthetic substrate (Bz-Phe-Val-Arg-pNA) in a model wine system after adding ethanol, sulfur dioxide (SO(2)), skin, seed, and gallic and ellagic tannins at the average range of their concentration in wine. All the inhibitors of stem bromelain activity tested turned out to be reversible. Ethanol was a competitive inhibitor with a rather limited effect. Gallic and ellagic tannins have no inhibitory effect on stem bromelain activity, while both seed and skin tannins were uncompetitive inhibitors. The strongest inhibition effect was revealed for sulfur dioxide, which was a mixed-type inhibitor for the enzyme activity. This study provides useful information relative to a future biotechnological application of stem bromelain in winemaking.
authors.affiliation: Department of Food Science and Technology, University of Tuscia, via S. Camillo de Lellis, 01100 Viterbo, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Esti
authors.forename: Ilaria
authors.initials: I
authors.lastname: Benucci
authors.forename: Katia
authors.initials: K
authors.lastname: Liburdi
authors.forename: Anna Maria Vittoria
authors.initials: AM
authors.lastname: Garzillo
mesh_terms: D031230:Ananas / Q000201:enzymology*; D001963:Bromelains / Q000037:antagonists & inhibitors* / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D000431:Ethanol / Q000494:pharmacology; D007700:Kinetics; D013458:Sulfur Dioxide / Q000494:pharmacology; D013634:Tannins / Q000494:pharmacology; D014920:Wine / Q000032:analysis*
chemical_list: D004791:Enzyme Inhibitors; D013634:Tannins; D013458:Sulfur Dioxide; D000431:Ethanol; D001963:Bromelains; C091760:stem bromelain